<?php
if (!defined('LEVERSION')) exit('No direct script access allowed');

/**
 * 验证码
 */
class ValidateCode {
    private $charset  = 'ABCDEFGHJKMNPQRSTUVWXYabcdefghjkmnpqrstuvwxy23456789'; // 随机因子
    private $code;                    // 验证码
    private $codelen  = 4;            // 验证码长度
    private $width    = 80;           // 宽度
    private $height   = 39;           // 高度
    private $img;                     // 图形资源句柄
    private $font;                    // 指定的字体
    private $fontsize = 18;           // 指定字体大小
    private $fontcolor;               // 指定字体颜色
                        
    // 构造方法初始化
    public function __construct() {
        $this->font = '../static/font/elephant.ttf';
    }
    
    // 生成随机码
    private function createCode() {
        $_len = strlen($this->charset) - 1;
        for ($i = 0; $i < $this->codelen; $i++) {
            $this->code .= $this->charset[mt_rand(0, $_len)];
        }
    }
    
    // 生成背景
    private function createBg() {
        $this->img = imagecreate($this->width, $this->height);
        $color = imagecolorallocate($this->img, mt_rand(157, 255), mt_rand(157, 255), mt_rand(157, 255));
        // $color = imagecolorallocate($this->img,255,255,255);
        imagefilledrectangle($this->img, 0, $this->height, $this->width, 0, $color);
    }
    
    // 生成文字
    private function createFont() {
        $_x = $this->width / $this->codelen;
        for ($i = 0; $i < $this->codelen; $i++) {
            $this->fontcolor = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
            imagettftext($this->img, $this->fontsize, mt_rand(-30, 30), $_x * $i + mt_rand(1, 3), $this->height / 1.4, $this->fontcolor, $this->font, $this->code[$i]);
        }
    }
    
    // 生成线条、雪花
    private function createLine() {
        for ($i = 0; $i < 3; $i++) {
            $color = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
            imageline($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $color);
        }
        for ($i = 0; $i < 10; $i++) {
            $color = imagecolorallocate($this->img, mt_rand(200, 255), mt_rand(200, 255), mt_rand(200, 255));
            imagestring($this->img, mt_rand(1, 5), mt_rand(0, $this->width), mt_rand(0, $this->height), '*', $color);
        }
    }
    
    // 输出
    private function outPut() {
        header('Content-type:image/png');
        imagepng($this->img);
        imagedestroy($this->img);
    }
    
    // 对外生成
    public function doimg() {
        $this->createBg();
        $this->createCode();
        $this->createLine();
        $this->createFont();
        $this->outPut();
    }
    
    // 获取验证码，验证码都转换成小写
    public function getCode() {
        return strtolower($this->code);
    }
}

